Tissues Class 9 Notes Science - Chapter 6

Chapter: 6

What Are Tissues ?

A group of cells that are similar in structure and/or work together to achieve a particular function forms a tissue.

Plant Tissues

Meristematic Tissue
(Immature cells capable of divisions)
  • Apical Meristem (Present at the growing tips of stems and roots responsible for increase in length)
  • Intercalary Meristem (Present at the bone of internodal regions, responsible for secondary growth)
  • Lateral Meristem (Present in lateral regions, responsible for increase in width of the plant)

Permanent Tissue
(Mature cells incapable of divisions)

  • Simple (Made up of only one type of cells)
  • Parenchyma (Living tissue stores and condusts food, water and minerals)
  • Collenchyma (Living tissue provides strength and flexibility to growing part of the plant)
  • Sclerenchyma (Dead tissue, provides mechanical support)
  • Complex (Protecting and supporting)
Xylem

(Conducts water and mineral from the root to the steam and leaves)

  • Tracheids (Elongated tube like with thick lignified walls)
  • Vessels (Long cylindrical with lignified walls)
  • Fibres (Highly thickned walls)
  • Xylem parenchyma (Living cells, thin walled)
Phloem

(Transport food from the leaves to the other parts)

  • Sieve tube elements (Long, tube like, arranged longituinally)
  • Companion cells (Specialised parenchyma)
  • Phloem parenchyma (Long cylinrical, stores food)
  • Phloem fibre (Made of sclerenchyma, thick cell wall)

Animal Tissues

Epithelial tissue

(Protective tissue)

Glandular
(specialised tissue)

  • Salivary gland

Unilayer

Multilayer

  • Stratified squamous epithelium

Squamous (Thin and flat forming living of blood vessels, alveoli, mouth and Oesophagus)

Cuboidal (Cube shaped, form livings of renal tubule and duct of salivary glands where it provides mechanical support)

Columnar
(Pillar like)

  • Non-ciliated (Tall cells in inner linings of stomach and intestine)
  • Ciliated columnar epithelium (Tall epithelial cells with hair like projections, present in inner lining of respiratory tract)

Muscular tissue

(Responsible for movements in body)

Voluntary muscle
(Activities under the control of
nervous system) or Skeletal muscle

Involuntary muscle
(Responsible for involuntary
movement in body)

  • Cardiac Muscle
    (Cylindrical, branched, uninucleate and straited)
  • Smooth/unstriated
    muscles or Visceral
    Muscle (Located in the
    inner wall of hollow
    visceral organs like
    alimentary canal, etc.)

Connective tissue

(Linking and supporting
tissues or organs of body)

  • Bone (strong, non-flexible tissue compound of bone cells and hard matrix of calcium and phosphorus)
  • Ligament (Elastic tissue with little matrix, connect bone to bone)
  • Tendous (Fibrous tissue with great strength and limited flexibility – connect muscle to bone)
  • Cartilage (Alidely spaced cells, smoothens bone surface at joints)
  • Areolar  connective Tissue (Found between skin and muscle around blood vessels and nerves and in bone marrow)

Nervous tissue

(Receives, conduct and transist electrical impulse, made up of
nervous or nerve cells)